Bicycloheptene carboxylates and their production



BICYCLOHEPTENE CARBOXYL'ATES AND THEIR PRODUCTION Fred W. Banes,Westfield, and Herbert K. Wiese, Cranford, N.J., assignors to EssoResearch and Engineering Company, a corporation of Delaware No Drawing.Application April 1, 1955 Serial No. 498,749

13 Claims. (Cl. 260468) This invention relates to polyfunctionalderivatives of cyclodiene carboxylic acids and to their preparation.More particularly the invention relates to carboxylic compounds obtainedby reacting a dicyclopentadiene dicarboxylic acid with variousunsaturated compounds such as styrene, butadiene, acrolein, methyl vinylketone, tung oil, and so forth.

Dicyclopentadiene dicarboxylic acids and their preparation have beendescribed previously in copending application of Cohen et al., SerialNo. 268,122, filed January 24, 1952, issued as Patent 2,716,662;reissued as Re. 24,123. Such acids are in eifect dimers of thecorresponding monocyclodiene monocarboxylic acids.

It is well known that dicyclodiene hydrocarbons can be depolymerizedinto isolatable monomers. For example, dicyclopentadiene can bedepolymerized to cyclopentadiene monomers which can be isolated and usedfor preparing other derivatives of polymers thereof. Although acyclodiene monocarboxylic acid monomer is a very desirable intermediatefor producing valuable derivatives, it has been found impossible toisolate such a monocarboxylic acid monomer by depolymerizing adicyclodiene dicarboxylic acid. When attempting to depolymerize adicyclodiene dicarboxylic acid to a monomer by heating, as is done inthe case of a dicyclodiene hydrocarbon, the dicarboxylic acid eitherdecarboxylates or resinifies or both.

It has now been found that derivatives of a cyclodiene monocarboxylicacid monomer can be readily obtained by heating a dimeric dicyclodienedicarboxylic acid in the presence of a suitable unsaturated, dienophiliccompound. That is, although it is impossible to depolymerize adicyclodiene dicarboxylic acid by itself, it is possible to shift theequilibrium to the monocarboxylic acid monomer whenever a reactivedienophilic compound is present to react with the monomer acid as soonas it is produced.

Accordingly, the principal reagent used in carrying out the presentinvention is a dicyclodiene dicarboxylic acid such as dicyclopentadienedicarboxylic acid having the formula:

HOOC COOH Other dicarboxylated dicyclodiene compounds suitable for thepresent purposes are dimethyl dicyclopentadiene dicarboxylic acid, i.e.,the dicarboxylated dimer of methylcyclopentadiene, or methyldicyclopentadiene dicarboxylic acid, i.e., the mixed dimer ofcyclopentadiene carboxylic acid and methyl cyclopentadiene carboxylicacid. The corresponding alkyl esters, e.g. the dimethyl ester ofdicyclopentadiene dicarboxylic acid can be used likewise.

The other essential reagent used in the present invention is a reactiveunsaturated dienophilic compound such as an unsaturated ketone oraldehyde, a conjugated diene "ice or other reactive unsaturatedhydrocarbon, nitriles of unsaturated acids, or triglycerides ofunsaturated acids. Representative compounds include vinyl ketones suchas methyl vinyl ketone; acrolein, croton-aldehyde and other aldehydescontaining a double bond adjacent to the carbonyl group; allyl alcohol,cinnamyl alcohol and similar unsaturated alcohols; conjugated dienessuch as isoprene, butadiene-1,3, piperylene or chlorinated derivativessuch as chloroprene; vinyl compounds such as styrene, acrylonitrile,methacrylonitrile, vinyl chloride, vinylidene chloride; and triglycerideesters of unsaturated aliphatic acids such as oleic, linoleic,eleostearic or linolenic acid either in substantially pure form or inthe form of vegetable or animal oils such as tung oil, linseed oil,soybean oil, menhadden oil, etc.

Broadly the depolymerization and reaction with dienophilic compounds toproduce derivatives of bicycloheptene containing at least one carboxylgroup can be depicted as follows:

(1) DEPOLYMERIZATION OF DIMER ACID ll i3 As a result, valuablederivatives of bicycloheptene are obtained which contain at least onecarboxyl group and wherein R=H, aryl (,CH etc.), alkyl (CH C H etc.);' R=H, COOH, COOR, CH0,

CH CN, Cl, aryl; R =H, CH COOI-I, R (CH C H CH:CH.CH etc). Sincereactions of the above type have normally been found to be quantitative,it is advantageous to use the reagents in stoichoimetric proportions,that is, one mole of the dimeric dicyclodiene dicarboxylic acid per twomoles of the unsaturated dienophilic compound. However, an excess of oneor the other reagent may be present if desired for any special reason,e.g. to serve as a diluent. No catalyst is required.

The reaction is carried out satisfactorily by heating the reactionmixture at a temperature sufficiently high to produce the monomericcyclodiene monocarboxylic acid by cracking or depolymerization of thedicyclodiene dicarboxylic acid. Suitable reaction temperatures are inthe range of about to 250 C., preferably 135 to 190 C. Below about C.the reaction tends to become slow due to the low rate ofdepolymerization and consequent small availability of the requiredmonomeric acid. On the other hand at temperatures above 190 C.decarboxylation of the dicyclodiene dicarboxylic acid and resinificationbecome increasingly noticeable.

The reaction pressure depends on the nature of the reaction ingredientsused and on the temperature of reaction. Accordingly, the process of theinvention may be conveniently conducted at pressures ranging fromatmospheric or slightly subatmospheric to moderately elevated pressuressuch as 10 or 50 p.s.i.g. The reaction is a rapid one and can normallybe completed in about 5 to minutes, reaction times of about 10 to 60minutes commonly being satisfactory. The reaction can be-carried outeither batchwise or in a continuous manner.

The reaction is suitably controlled by refluxing a solvent medium suchas xylenes, straight run mineral spirits (Varsol), nonanes, decanes,propionic acid, and other liquids which are substantilly inert in thereaction mixture and boil in the desired reaction temperature range whenunder suitable pressure. About 2 to parts by weight of such a liquid perpart by weight of cyclodiene carboxylic acid are convenient to use.However, the reaction can be conducted without any solvent, using othertemperature control means. Nevertheless, use of the solvent isbeneficial since it improves contact between the reagents and usuallytends to promote depolymerization of the dimeric acid.

Examples'illustrative of the scope and operation of the invention aresummarized in Tables I and II. It will be understood that all amounts,ratios, and percentages of materials are expressed on a weight basisthroughout this specification and in the appended claims, unlessotherwise indicated.

Table I illustrates some of the principal reactions carried out inaccordance with the present teaching and shows the types of productsobtainable.

Table I.Reaction of dicyclopentadiene dicarboxylic acial with variousdienophilic compounds to produce derivatives of dicyclo (2,2,1)hept5-ene containing at least C'P.CO 0H Eleostearic Acid v Triglycerideof 3-butyl-7-carboxy-dicyclo(2,2,1)- hept-5-ene-2-dodecadien 8,10 oicacid *1 Used the dimethyl ester of dicylopentadiene dicarboxylic acid.

b Used in the form of a glyceride present in tung oil.

Table 11 gives a detailed summary of several typical runs whereindicyclopentadiene dicarboxylic acid, hereafter abbreviated as DCPDA, wasreacted with various dienophilic compounds under specified conditions.The

Dimer acid Cyclopentadiene mono- ID carbpxyllc 801d reactions wereconducted at atmospheric pressure in an (abbreviated below as HCROOOH")agitated reactor.

Table II.Reactzon of dzcyclopentadrene dzcarboxylzc acid Wllh variousdzenophlles Run N o 61 133 103 Charge:

DCPDA, gm 2 I 20 l 25.

Other Reagent, gm Styrene, 97.5.--- tung oil, 5.. Acrolein, 75Crotonaldehyde, 21

Solvent, ml nonenone none l50-iylene Conditions:

ax. Temp C -140 180 lfii 165.

Time at Max Temp, min. 45 15 1; 15. Recovered, gm 25 b .4 26 146 B 31Yield, Mole, percent, and Based on DOPDA 64.5 o Analysis of Product:

Acid No., me /gm. 5.43 (4.67) 5.70 5.55

Hydroxyl No., meq./gm. 4.94 (5.43).- 4.81 (0.00M

Molecular Weight B 221 (214) Appearance Viscous Liquid. Viscous Liquid.Liquid Solid Br, N 0., meq. Bri/grn. 4.91 (4.67)

a Figures in parenthesis represent theoretical values.

11 Products duet with 50% E280 worked up by dissolving adduct in aqueousK3003 followed by'extraction with petroleum ether and springing ado Theremaining 35.5% was converted to copolymer with styrene. d Reaction withelcostearic acid present as glyceride in tung oil. About 73.0% of fattyacids present in tung oilconsist of elecstearic acid.

Occurence of reaction evidenced by failure of insoluble DCPDA toprecipitate out on cooling reaction mixture and formation of emulsionduring titration of same.

1 Used the dimethyl ester of same.

a Product recovered after hydrogenation of adduct to saturate doublebond and convert aldehyde group to hydroxyl group.

Excess acrolein removed prior to hydrogenation. Used Raney nickel ascatalyst at 150 0. and 2000 p.s.1.g. Hg.

Distillation oi hydrogenated product yielded 10.3% front ends, 66.1%heart out and 33.9% residue which includes hold up of column.

11 Based on heart cut (see (s)).

l O, H, O values: found, 64.1% C, 29.1% 0, 6.8% H. Theoretical values:66.6% C, 26.7% 0, 6.7% H.

Low carbonyl number and the presence of formed from the carboxyl II-Aonooon Acrolein HOOC 7o 6 I 2 CH0 1 7-carbmethoxy-dicyclo (2,2,1)hept-5-ene-2-al The product was later hydrogenated to obtain7-carbmethoxy-dicyclo (2,2,1) heptan-Z-ol.

hydroxyl groups indicates the presence of oxylactone (heini acctal)group and aldehyde group present in the same molecule.

Since the obtained 'carboxylated bicycloheptene derivatives contain atleast one double bond, they can undergo many reactions such asoxonation, epoxidation, halo- 70 genation, hydroxylation, hydrogenationand addition of 5 goup can b oxidid to-an acid, or reduced to anunsaturated or saturated alcohol, depending on hydrogenation conditions.A reduction of the latter type was carried out in connection with runNo. 133 as described in footnote (g) of Table II. The resultingmaterials of the type represented by the resulting product contain botha hydroxyl and a carboxyl group and can be used in making polyester-typesynthetic lubricants, resins, in modifying natural drying oils, and thelike. Other uses include the preparation of agricultural chemicals. Someof the chlorinated carboxylated derivatives, in particular, havepesticidal properties and can be used as such, or as alkyl esters, or inthe form of salts of metals such as copper, mercury, lead, or the like.

The described invention is claimed as follows:

1. A dicycloheptene derivative which comprises an adduct of acyclopentadiene derivative selected from the group consisting ofcyclopentadiene monocarboxylic acid, methylcyclopentadienemonocarboxylic acid, and the methyl esters thereof, and an unsaturateddienophilic compound having the formula R R wherein R is selected fromthe group consisting of hydrogen and alkyl and aryl radicals; R isselected from the group consisting of hydrogen, carboxyl, carbalkoxyl,formyl, alkylformyl, cyano, chlorine and aryl radicals; and R isselected from the group consisting of hydrogen, carboxyl,carboxyalkenyl, carboxyalkadienyl, aryl, alkyl, and alkylene radicals.

2. An adduct according to claim 1 wherein the dienophilic compound is aglyceride of an unsaturated aliphatic monocarboxylic acid.

3. An adduct according to claim 1 wherein the dienophilic compound is aglyceride of an octadecadienoic acid.

4. An adduct according to claim 1 wherein the dienophilic compound is avinyl substituted hydrocarbon.

5. A carboxy-dicyclo (2,2,1)-hept-5-ene-2-al.

6. Carbmethoxy-dicyclo(2,2,1)-heptan-2-ol.

7. A process for preparing carbmethoxy-dicyclo (2,2, 1) heptan-2-olwhich comprises mixing one mole of the dimethyl ester ofdicyclopentadiene dicarboxylic acid with about two moles of acrolein,refluxing the mixture in an inert liquid solvent at a temperature in therange of 135 to 190 C. and a pressure between about atmospheric and 50p.s.i.g., contacting the resulting carbmethoxy-dicyclo (2,2,1)hept-S-ene-Z-al with sufiicient hydrogen over a hydrogenation catalystat a sufiicient temperature and pressure to saturate the double bond andconvert the aldehyde group to an alcohol group, and recovering theproduct carbmethoxy-dicyclo (2,2,1) heptan-2-ol.

8. A process of preparing a carboxylated dicycloheptene derivative whichcomprises mixing a dicarboxylated dicyclopentadiene with an unsaturateddienophilic compound having the formula wherein R is selected from thegroup consisting of hydrogen and alkyl and aryl radicals; R is selectedfrom the group consisting of hydrogen, carboxyl, carbalkoxyl, formyl,alkylformyl, cyano, chlorine and aryl radicals; and R is selected fromthe group consisting of hydrogen, carboxyl, carboxylalkenyl,carboxyalkadienyl, aryl, alkyl, and alkylene radicals and heating themixture at a temperature between about and 250 C.

9. A process according to claim 8 wherein the dicarboxylateddicyclodiene is selected from the group consisting of dicyclopentadienedicarboxylic acid, dimethyldicyclopentadiene dicarboxylic acid,methyldicyclopentadiene dicarboxylic acid, and alkyl esters thereof. 10.A process according to claim 9 wherein the dienophilic compound isselected grom the group consisting of unsaturated aldehydes, vinylsubstituted hydrocarbons, and triglycerides of octadecadienoic acids.

11. A process of preparing a carboxylated dicycloheptene derivativewhich comprises mixing the methyl ester of dicyclopentadienedicarboxylic acid with a molecular excess of acrolein and heating theresulting mixture at a temperature between about and C.

12. A process of preparing a carboxylated derivative of dicycloheptenewhich comprises mixing dicyclopentadiene dicarboxylic acid with avegetable drying oil and berating the mixture at a temperature of about135 to 19 C.

13. A process according to claim 12 wherein the vegetable oil is tllngoil.

References Cited in thefile of this patent UNITED STATES PATENTS2,415,453 Thomas Feb. 11, 1947 2,688,627 Cohen et a1. Sept. 7, 19542,716,662 Cohen et al Aug. 30, 1955

1. A DICYCLOHEPTENE DERIVATIVE WHICH COMPRISES AN ADDUCT OF ACYCLOPENTADIENE DERIVATIVE SELECTED FROM THE GROUP CONSISTING OFCYCLOPENTADIENE MONOCARBOXYLIC ACID METHYLCYCLOPENTADIENE MONOCARBOXYLICACID, AND THE METHYL ESTERS THEREOF, AND AN UNSATURATED DIENOPHILICCOMPOUND HAVING THE FORMULA
 6. CARBMETHOXY-DICYCLO(2,2,1)-HEPTAN-2-OL.7. A PROCESS FOR PREPARING CARBMETHOXY-DICYCLO (2,2, 1) HEPTAN-2-OLWHICH COMPRISES MIXING ONE MOLE OF THE DIMETHYL ESTER OFDICYCLOPENTADIENE DICARBOXYLIC ACID WITH ABOUT TWO MOLES OF ACROLEIN,REFLUXING THE MIXTURE IN AN INERT LIQUID SOLVENT AT A TEMPERATURE IN THERANGE OF 135* TO 190*C. AND A PRESSURE BETWEEN ABOUT ATMOSPHERIC AND 50P.S.I.G., CONTACTING THE RESULTING CARBMETHOXY-DICYCLO (2,2,1)HEPT-5-ENE-2-AL WITH SUFFICIENT HYDROGEN OVER A HYDROGENATION CATALYSTAT A SUFFICIENT TEMPERATURE AND PRESSURE TO SATURATE THE DOUBLE BOND ANDCONVERT THE ALDEHYDE GROUP TO AN ALCOHOL GROUP, AND RECOVERING THEPRODUCT CARBMETHOXY-DICYCLO (2,2,1) HEPTAN-2-OL.
 8. A PROCESS OFPREPARING A CARBOXYLATED DICYCLOHEPTENE DERIVATIVE WHICH COMPRISESMIXING A DICARBOXYLATED DICYCLOPENTADIENE WITH AN UNSATURATEDDIENOPHILIC COMPOUND HAVING THE FORMULA